Right channel on Luxman M-117 amp comes out of both speakers

headrott

F1nut wrote: »

DO NOT switch your amp to bridged mode!

The left channel in the Luxman is dead. Since you own SDA's, even though the left amp channel is dead with the SDA cable connected the left speaker will still produce some sound because of the crosstalk signal from the right speaker.

Check for a bad external or internal left channel fuse. If the fuse is good, it may have a bad left channel relay. Anything more than that and it's not worth messing with. Since you already got a refund, throw it out with the trash.

Thanks for the advice of not switching the amp to bridged mode, I did not because I had a feeling that was not the problem. Of course! I didn't even think about the SDA effect comming through on the left channel! Thank you F1nut! That makes sense.

What does not make sense is the fact that the gain adjustment for the right channel adjusts the gain while using both the variable RCA jacks AND the fixed jacks. The fixed should be just that right? The gain should not change while using those inputs, correct?

Sorry for posting in 2 forums

heiney9

Great catch Jesse! I guess no one realized or paid attention to the fact that he had SDA's and the dimensional drivers in the opposite channel were what was giving the sound.

Sort of a DUH moment now that I look back on it

H9

headrott

OK, I found out the problem with the M-117 amp. That dent in the rear by the left channel binding post put a crack through the speaker terminal board. It runs 3/4 of the way through it. It only affected the left channel, but not the right. I will take it out and try to re-solder the connections to see if I can get the left channel to work again. It will need a new board though. Does anyone have ideas on where to get one (other than buying a non-working M-117)?

Polkersince85

You could just try soldering a jumper wire from point A to point B.

F1nut

If the traces are damaged and it seems like they are, you don't need to replace the board. After repairing the crack on the none trace side with a good adhesive like epoxy, you can solder solid core wire on top of the traces to restore continuity.

headrott

OK, I will try to solder the wire to restore the continuity. Do you think the epoxy will keep the board from cracking more even over years? To give you an idea of how badly it's cracked; 3 of the 4 corners of the board were broken off where they are screwed onto the back of the amp.

F1nut

Epoxy is very strong stuff, but there are different qualities of epoxy products and the best repair method will vary. For the best repair possible I use West Marine epoxy products, but they are not cheap.

For a cheaper approach to your situation I would suggest using one of the 5 minute epoxy products and fiberglass cloth. Cut the cloth to size first, then apply a layer of epoxy to the damaged area. Next, lay the cloth over the epoxy and press/rub it so that the epoxy starts to soak into the cloth. Working quickly, apply more epoxy on top of the cloth. Do one damaged area at a time.

When you've done all 3 areas, let it all harden up for 24 hours before reinstalling. Done right, you will never have another problem with the damaged areas.

bluecomet

I had a feeling the problem was where the dent was and bingo, cracked board. I doubt if that happened during shipping. The seller was unloading that amp. I hope you get the refund, fix the amp and enjoy the amp for years to come. If it all works out you will get the amp for the price of fixing the board and shipping. It may turn out to be a great deal for you. Good luck.